OBJECTIVETo explore the relationship between the optical density index of serum aspergillus galactomannan (GM) assay and invasive aspergillosis (IA).

METHODSFrom Jan 2008 to Dec 2011, 825 hematological diseases patients with neutrophil count <0.5×10⁹/L⁹ by continuous blood count tests were admitted into our hospital. The optical density index of GM assay was ≥0.5 at least once. Of 825 patients, 247 cases were manifested as fever during hospitalization. The optical density index of GM antigen was detected by enzyme-linked immunosorbent assay, and the sensitivity and specificity of optical density ranged in 0.5-1.5.

RESULTSIn this study, the sensitivity and specificity of GM assay with continuous twice samples (73% and 93%, respectively) were higher than single sample (66% and 80%, respectively) when optical density index ≥1.0. 69 cases were diagnosed as proven IA with the incidence rate of 8.36%.

CONCLUSIONThe cut-off level for serum GM antigen assay should be decided as optical density index in two continuous samples of ≥1.0.

Adolescent ; Adult ; Aged ; Antigens, Fungal ; blood ; Aspergillosis ; blood ; diagnosis ; etiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Hematologic Diseases ; blood ; microbiology ; Humans ; Male ; Mannans ; blood ; immunology ; Middle Aged ; Sensitivity and Specificity ; Young Adult

BACKGROUND/AIMS: In this study, the sensitivity-specificity of galactomannan-enzyme immunoassay (GM-EIA) with a cut-off value of 0.5 for a single, two, or three consecutive positivity in the diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients with hematological malignancy was investigated. METHODS: IPA was classified as "proven," "probable," or "possible" as described in the guidelines prepared by the European Organization for Research and Treatment of Cancer and Mycoses Study Group." Serum samples were collected from the patients twice a week throughout their hospitalization. A total of 1,385 serum samples, with an average of 8.3 samples per episode, were examined. RESULTS: Based on the 165 febrile episodes in 106 patients, 80 (48.5%) were classified as IPA (4 proven, 11 probable, 65 possible) and 85 (51.5%) as non-IPA. The sensitivity/ specificity was 100%/27.1% for a single proven/probable IPA with the cut of value of GM-EIA > or = 0.5, 86.7%/71.8% for two consecutive positive results, and 73.3%/85.9% for three consecutive positive results. CONCLUSIONS: With the galactomannan levels measured twice a week, consecutive sensitivity decreased and specificity increased. Therefore, an increase may be obtained in sensitivity-specificity by more frequent monitoring of GM-EIA starting from the first day of positivity is detected.
Adult ; Aged ; Antineoplastic Agents/*adverse effects ; Biomarkers/blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Hematologic Neoplasms/diagnosis/*therapy ; Hematopoietic Stem Cell Transplantation/*adverse effects ; Humans ; Immunocompromised Host ; Immunosuppressive Agents/*adverse effects ; Invasive Pulmonary Aspergillosis/*blood/diagnosis/immunology/microbiology ; Male ; Mannans/*blood ; Middle Aged ; Opportunistic Infections/*blood/diagnosis/immunology/microbiology ; Predictive Value of Tests ; Reproducibility of Results ; Time Factors

We compared a real time-nucleic acid sequence-based amplification (RTi-NASBA) with conventional NASBA, galactomannan enzyme immunosorbent assay (GMEIA), and Mycology Study Group of the European Organization for Research and Treatment of Cancer (EORTC/MSG) criteria for the diagnosis of invasive aspergillosis (IA). From May 2004 to May 2005, blood samples (314 in total) were collected twice a week from 78 patients with hematologic diseases during neutropenic fever after chemotherapy or hematopoietic stem cell transplantation. Results were compared with each other on the basis of EORTC/ MSG criteria. The cutoff of conventional NASBA was set to be 3.5; GM 0.5; RTi-NASBA, 20% above the negative control. There were 22 patients with IA (7 probables and 15 possibles) and 56 patients with nonfungal infection. The Kappa statistic for RTi-NASBA versus conventional NASBA was 0.80 (0.66-0.82; p<0.001) indicating that there was fairly good accordance between two tests. RTi-NASBA showed sensitivity 0.96, specificity 0.43, positive- and negative-predictive value 0.40 and 0.96, respectively. GM showed good specificity (0.98), while the sensitivity (0.45) was poor. When we use the combination of GM with either of two NASBAs, the sensitivity was improved up to 100%. In conclusion, RTi-NASBA could be a good alternative to the conventional one for the screening of IA.
Aspergillosis/blood/*diagnosis/microbiology ; Aspergillus/*genetics/metabolism ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Mannans/*blood ; Nucleic Acid Amplification Techniques/*methods ; RNA, Fungal/genetics/isolation & purification ; Reproducibility of Results ; Sensitivity and Specificity

The objective of this study was to explore the useful value of circulating galactomannan (GM) for early diagnosis of invasive aspergillosis. All 141 patients were classified as 103 patients of clinical and possible diagnosis, and 38 non-Aspergillus patients. 209 serum samples for the detection of GM by Platelia Aspergillus were collected before anti-fungal vaccine therapy. ELISA method was used in detection of GM. The results showed that (1) the sensitivity of 87.5%, specificity of 81.6%, positive prediction of 66.7% and negative prediction of 93.9% were determined by using cut-off value. According to the result of ELISA, the clinical diagnosed patients was up to 48, while the possible diagnosed patients were 55. (2) Among 62 patients with consecutive examinations of serum samples, 50 patients were successfully diagnosed and treated, while 12 patients died. A progressive reduction of GM level was found in survivors, however, the patients of poor prognosis showed higher antigen titres. It is concluded that GM test has more significance for earlier diagnosis of aspergillosis, the concentration of GM is related to prognosis of disease.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Aspergillosis ; diagnosis ; Aspergillus ; Enzyme-Linked Immunosorbent Assay ; Female ; Hematologic Diseases ; diagnosis ; microbiology ; Humans ; Male ; Mannans ; blood ; Middle Aged ; Predictive Value of Tests ; Sensitivity and Specificity ; Young Adult